1. Field of the Invention
This invention is directed to apparatus, systems, and methods for unloading, vaporizing, storing, and supplying natural gas in fluid form. The invention further relates to containers and transportation lines for carrying and transporting natural gas and other fluid forms.
2. Description of the Background
Current systems and methods for unloading and storing natural gas (NG) are both expensive and difficult to manage. When NG is transported in bulk, other than by pipeline, it typically is in liquid form, which requires extreme refrigeration for a reduction in temperature sufficient to form a liquid. When the liquid NG (LNG) arrives at a given destination, it is offloaded from transport tankers and stored onshore in specialized storage facilities while still in a liquid state. This unloading and land based storage of LNG causes difficulties that prohibit the proliferation of NG use in countries such as the United States.
At some point in the process of getting NG to the consumer, LNG is returned to a gaseous state. Even in the gaseous state, storage of LNG requires pressurized facilities, which presents both actual and perceived risks. Both types of risks stem from safety concerns, specifically catastrophic failure of the storage tanks, and under certain circumstances, followed by explosions and fire. Although current technology minimizes the risk of accidents, it cannot mitigate the risk of terrorism related failures. This fear has led many communities to refuse permission for the building of construction of unloading facilities and storage facilities.
Due to public safety concerns, stringent regulations are often put into place controlling when and where LNG tankers are permitted to dock. Other commercial and recreational boat traffic is often diverted when LNG tankers are present. This disruption to other businesses is a significant financial burden for every community in which there exists LNG traffic. Expenses related to offloading NG are already significant. Those expenses are significantly increased when considering all the safety precautions that must be taken into account.
One mechanism to address these concerns is disclosed in U.S. Pat. Nos. 4,325,656; 5,511,905; 6,530,240; 6,555,155; 6,584,781; 6,725,671; 6739,140; 6,813,893; 6,848,502; 6,880,348 and 6,945,055 (the disclosures of which are all hereby specifically incorporated by reference). These United States patents address concerns of LNG storage and propose storage of LNG in salt caverns. However, there are problems associated with thermal shock where the very cold NG hits the warmer cavern walls and creates unwanted and destructive fissures. Further, there is unwanted mixing of the LNG with seawater.
Onshore facilities built to store NG in a liquid state, and then to convert the LNG into gas at some later time is also extremely costly. New systems and methods for unloading and gasifying LNG without incurring the economically unreasonable costs are needed to enlarge the NG market domestically and abroad.